Slow, sometimes indulgently slow. Presented in scenes out of sequence. Strong acting by Sean Penn (always good), Naomi Watts (also -- always good), and Benicio Del Toro (yes -- you can count on him too). With a cast like that, you know this is going to be a rather intense film. But that intensity is diluted with a languid pace. I don't see how editing out of the timeline adds to this film. And the music/sound track, while contributing to the harsh reality of the picture's subject, ultimately subtracts from the entertainment.

An interesting concept, but, at least for me, not a very spectacular scripting of that concept. The film deals with the entanglements of three families. Sean Penn is a Math Professor dying from heart disease (presumably), Naomi plays a woman dealing with the sudden death of her husband and two girls, and Benicio is a born-again ex-con. The interesting concept is that of a heart transplant and how this affects the lives of those involved. But the film spends too little time on those nuances (although that time is well spent) and too much time on a less meaningful plot.

A puzzle at first, but by half way you may have figured it out, then it's a wait until the end. That said, each character's personal struggle with his or her course harsh reality is aptly realized.

Btw, 21 grams is supposedly the weight each of us loses upon dying.